In his 300th NASCAR Sprint Cup start, Kahne posted his first victory of the season, his first since joining Hendrick Motorsports and the 13th of his career. The win was Kahne's fourth at Charlotte.

Kahne beat runner-up Denny Hamlin to the finish line by 4.295 seconds. Kyle Busch ran third, followed by Greg Biffle, Brad Keselowski and Dale Earnhardt Jr., as nine cars finished on the lead lap at the 1.5-mile track.

Biffle extended his series lead to 10 points over Roush Fenway Racing teammate Matt Kenseth, who finished 10th, the first driver one lap down. Hamlin is third in the standings, 15 points back and one spot ahead of Earnhardt, who trails Biffle by 18 points.

Kahne said he never lost confidence, despite a miserable start to his season.

"I never doubted myself," said Kahne, who has recorded top-10 finishes in his last six points races after an average result of 28.5 in his first six races for Hendrick. "I was upset at some of the things that may have happened. I made a huge mistake at Phoenix and hit the wall there (in the second race of the season), but other than that, we were solid -- we were fast.

"It was just a matter of getting past those (six) weeks and moving on and putting some solid races together."

After his final pit stop under green on Lap 354 of 400, Hamlin trimmed Kahne's advantage to less than a second early in the run but fell back as the race continued.

"As the track cooled off, it freed up for us -- the car got better," Hamlin said. "Ultimately, it gave us a shot to win. . . . The first 10 laps of the last run, we got to them (Kahne), but we wore our front tires trying to get around them.

"Everything was executed great today, the pit calls, getting on and off pit road, the pit crew themselves. We had a very, very solid day."

A caution on Lap 319 for debris in Turn 3 interrupted some of the best racing of the night. Before the yellow, Biffle and Kahne had swapped the lead repeatedly, with neither able to gain a clear advantage. Hamlin was in the mix, too, trailing the top two cars by less than a half-second.

Hamlin and Earnhardt stayed on the track under the caution, while the other eight lead-lap cars came to the pits on Lap 320 for two-tire and four-tire stops. After the subsequent restart on Lap 326, Kahne needed fewer than eight laps to blow past both Earnhardt and Hamlin into the lead.

On Lap 333, Kahne powered past Hamlin off Turn 2 and began to pull away. Kahne maintained an advantage of more than one second through a cycle of green-flag pit stops that began on Lap 353 when Biffle and Kyle Busch brought their cars to pit road.

That round of pit stops proved disastrous for Jimmie Johnson, who dragged a fuel can out of his pit stall and returned to pit road under green to serve a stop-and-go penalty. The miscue put Johnson a lap down and left Kahne and Hamlin to decide the race between them.

The race concluded in three hours, 51 minutes, 14 seconds -- the fastest-ever Coke 600 -- prompting Hamlin to suggest that "everyone's trying to get to last call." The average speed of 155.687 mph broke the record 151.952 mph set in 1995 when Bobby Labonte won NASCAR's longest race.